Storage of data and information, particularly upon magnetic media, is conveniently accomplished by recording such information on storage disks which are commonly configured in the form of openable packs. Physical storage of such disk packs is conveniently and efficiently accomplished by closing the pack with the disks closely confined. However, to utilize such stored information, it is required that the disk pack be opened at least at one position and that the selected information be accessed by a transducer head brought into close relationship with the selected disk. This method of information storage and retrieval is well known in the art. A number of devices have been proposed for accessing data stored on such disk packs. Almost universally, such suggestions involve defining a single opening in the stack between selected disks, and moving a transducer into the opening for information retrieval. Either the single transducer must index axially to the opening, or the pack itself is moved relative to the transducer head to permit access of the transducer head to the opening at the selected disk.
Devices to accomplish the desired opening of the disk pack involve relatively complicated and expensive expedients. Examples of such devices are to be found for instance, in U.S. Pat. Nos. 2,960,340, 3,229,269, 3,3130,393, 4,011,591 and 4,019,204.
As will be apparent from an examination of the teachings of the above specified U.S. Letters Patents both involved physical, and pnuematic means, are employed with accompanying mechanical complications, expense, and risk of failure.